Comment 3 for bug 862129

No, that's not quite right. Per policy (

  The package whose postrm is being called may have previously been deconfigured and only be unpacked, at which point subsequent package changes do not consider its dependencies. Therefore, all postrm actions may only rely on essential packages and must gracefully skip any actions that require the package's dependencies if those dependencies are unavailable.

In any case, samba already depends on update-inetd, which depends on libfile-temp-perl, which is provided by perl-modules, so it's clearly not a matter of adding a dependency. It does have some code to attempt to gracefully cope if update-inetd is missing, but (a) the check for update-inetd being present isn't there in all branches, and (b) in this case update-inetd is present but not all its dependencies are available.